New hardware, perhaps Retina-equipped MacBook Air, also likely on the program; webcast likely

Apple will again kick off its developer conference with a keynote, where top-tier executives, including CEO Tim Cook, will tout the newest versions of iOS and OS X, and likely introduce new hardware.

Apple will again kick off its developer conference with a keynote, where top-tier executives, including CEO Tim Cook, will tout the newest versions of iOS and OS X, and if past practice is any kind of guide, introduce new hardware.

As in years past, the keynote will start at 10 a.m. PT (1 p.m. ET) on the first day of the Worldwide Developers Conference (WWDC), June 2, Apple said in a revised online schedule. WWDC will run through June 6.

The keynote has been scheduled for two hours.

If Apple hews to its usual timetable, it will preview iOS 8 and OS X 10.10 at WWDC, give pre-release code of at least one, most likely iOS, to developers at the conference, then launch the new operating systems in the fall. The last three years Apple has waited until June's WWDC to hand developers an iOS SDK (software development kit), then unveiled new iPhones in September (2012 and 2013) or October (2011).

In three of the last four years, Apple also used the WWDC keynote to announce the month of availability for the new OS X upgrade, then launched the edition within weeks. Last year, however, it left users and developers guessing, and postponed the release until late October.

A fall launch of both iOS 8 and OS X 10.10 is most likely, assuming Apple wants to give developers time to digest changes and new APIs so they can prepare new apps and applications, or tweak existing ones.

If the company follows protocol, Cook will play a part in the keynote, as he has since taking over as chief executive from Steve Jobs in 2011. Craig Federighi, who heads both OS X and iOS development, will undoubtedly talk, with others, including Eddy Cue, the lead on Internet software and services, and Philip Schiller, Apple's top marketing executive, also stepping onto the stage.

Apple has gotten into the habit of introducing new hardware, often Mac refreshes, at WWDC; there's no reason to believe it will not continue the practice.

In 2013, Apple unveiled new MacBook Air laptops and gave developers a sneak peak at the radically revamped Mac Pro. The former was upgraded with Intel's next-generation Core processor, code named "Haswell," which dramatically boosted battery longevity; Apple also dropped prices on its two 13-in. configurations.

The Mac Pro did not ship until the very end of the year, however, and then only in limited quantities.

Most pundits expect another refresh of the MacBook Air this WWDC, hoping that Apple adds Retina-quality screens to the lightweight laptops to sync that line with the MacBook Pro.

Although Apple has not publicly committed to webcasting the WWDC keynote, the company has regularly done so. Last year, it restricted the webcast to its own hardware, or from an OS X-powered virtual machine.

Much of the WWDC's session schedule remained redacted Wednesday, with placeholders such as "You'll find out in a few days" and "It's still our little secret." Those session details will not be revealed until after the June 2 keynote.

Apple is keeping most of its developer sessions under wraps until after the June 2 keynote. (Image: Apple.)